scholarly journals Numerical Predication of Solidification Phenomena of Phase Change Material in Concentric Annulus Pipe

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Balqies A. Abbas ◽  
Mustafa B. Al-Hadithi
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Liquid Fraction ◽  
Outer Cylinder ◽  
Thermal Conditions ◽  
Force Convection ◽  
Pipe Surface ◽  
Tube Heat Exchanger ◽  
History Of ◽  
Fraction Distribution

Two-dimensional numerical simulation is performed aiming to understand the role of buoyancy force convection during restricted solidification of phase change materials (PCMs) inside a shell and tube heat exchanger according to annulus cross section. Where the transient history of PCM solidification evolution was studied. The governing equations of mass, momentum and energy are solved to study the solidification behavior inside the annulus geometry. The fluid flow in the mushy zone was accounted for using the Darcy drag source term in momentum, and the liquid percentage in each cell was updated using the enthalpy-porosity method. Thermal conditions of the outer cylinder insulated (adiabatic) and the inner cylinder at constant temperature (isothermal). The results are presents as a temperature contour and liquid fraction distribution in the domain. The predicted result shows the capturing phenomenon: primary heat conduction in all regions, then heat convection and conduction become dominant in the top and bottom regions, respectively. The max. and min. temperature changes near the outer pipe surface during 16 hrs. are 56.25% and 42.5%, respectively.

scholarly journals Enhancement of the Thermal Energy Storage Using Heat-Pipe-Assisted Phase Change Material

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6176 ◽  
Author(s):  
Hamidreza Behi ◽  
Mohammadreza Behi ◽  
Ali Ghanbarpour ◽  
Danial Karimi ◽  
Aryan Azad ◽  
...  
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Heat Pipe ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Liquid Fraction ◽  
Energy Storage Applications ◽  
Change Material

Usage of phase change materials’ (PCMs) latent heat has been investigated as a promising method for thermal energy storage applications. However, one of the most common disadvantages of using latent heat thermal energy storage (LHTES) is the low thermal conductivity of PCMs. This issue affects the rate of energy storage (charging/discharging) in PCMs. Many researchers have proposed different methods to cope with this problem in thermal energy storage. In this paper, a tubular heat pipe as a super heat conductor to increase the charging/discharging rate was investigated. The temperature of PCM, liquid fraction observations, and charging and discharging rates are reported. Heat pipe effectiveness was defined and used to quantify the relative performance of heat pipe-assisted PCM storage systems. Both experimental and numerical investigations were performed to determine the efficiency of the system in thermal storage enhancement. The proposed system in the charging/discharging process significantly improved the energy transfer between a water bath and the PCM in the working temperature range of 50 °C to 70 °C.

scholarly journals Designs of PCM based heat exchangers constructions for thermal energy storage tanks – examples and case study for selected design

2018 ◽  
Vol 70 ◽  
pp. 01010
Author(s):  
Marta Kuta ◽  
Dominika Matuszewska ◽  
Tadeusz Michał Wójcik
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
New Technologies ◽  
Tube Heat Exchanger ◽  
Change Material

Increasing energy consumption in residential and public buildings requires development of new technologies for thermal energy production and storage. One of possibilities for the second listed need is the use of phase change materials (PCMs). This work is focused on solutions in this area and consists of two parts. First one is focused on different designs of thermal energy storage (TES) tanks based on the phase change materials. The second part is the analysis of tests results for TES tank containing shelf and tube heat exchanger and filled with phase change material. Thermal energy storage tank is analyzed in order to use it in domestic heating and hot utility water installations. The aim of this research was to check the applicability of phase change material for mentioned purpose. Results show that using phase change materials for thermal energy storage can increase amount of stored heat. The use of properly selected PCM and heat exchanger enables the process of thermal energy storing and releasing to become more efficient.

scholarly journals Influence of Thermal Insulation’s and Phase Change Material’s Insertion within a Partition Wall on the Energy Consumption of a Conditioned Room under Adjacent Local Periodical Temperature Effect

2020 ◽  
Vol 307 ◽  
pp. 01024
Author(s):  
Nisrine Hanchi ◽  
Hamid Hamza ◽  
Rabiaa Idmoussa ◽  
Jawad Lahjomri ◽  
Abdelaziz Oubarra
Keyword(s):  
Energy Consumption ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Insulation ◽  
Phase Change Materials ◽  
Thermal Conditions ◽  
Thermal Activity ◽  
Partition Wall ◽  
Reduction Of Energy Consumption ◽  
Change Material

The aim of this work is to study the combined insertion effect of Phase Change Materials (PCM) and thermal insulation within a partition wall separating a conditioned room from an adjacent local which is under a periodic thermal activity. This is done by a comparative study with a reference wall under the same thermal conditions. The comparison criterion is the energy density transmitted to the local conditioned in established regime. The results show that the inclusion of thermal insulation and phase change material provides a significant reduction of energy consumption of the conditioned local; thereby a judicious choice of phase change material with thermal level and range melting temperature reduces further this reduction.

A Numerical Investigation of Constrained Melting of Nanostructure-Enhanced Phase Change Materials in a Rectangular Cavity Heated From Below

2012 ◽  
Author(s):  
Li-Wu Fan ◽  
Liang Zhang ◽  
Zi-Tao Yu ◽  
Xu Xu ◽  
Ya-Cai Hu ◽  
...  
Keyword(s):  
Natural Convection ◽  
Phase Change ◽  
Thermophysical Properties ◽  
Phase Change Materials ◽  
Numerical Study ◽  
Liquid Fraction ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Rectangular Cavity ◽  
Heat Of Fusion

A numerical study of constrained melting of nanostructure-enhanced phase change materials (NEPCM) consisting of eicosane and various loadings of CNTs in a rectangular cavity heated from below was performed. Assuming that the NEPCM are single-phase PCMs with homogeneous thermophysical properties, the problem was solved using a finite volume method based on the enthalpy-porosity scheme for solid-liquid phase change. The effective thermophysical properties of NEPCM were predicted using the mixture models and empirical equation with respect to the loading of CNTs. Three nominal Grashof numbers corresponding to three sizes of the cavity were considered. Evolutions of the constrained melting processes were presented by means of snapshots of the temperature contour at representative time instants. The melting rates and local heat transfer along the heated bottom were compared quantitatively based on the variations of the instantaneous liquid fraction and average Nusselt number over the bottom during melting, respectively. It was shown that at a given size of the cavity, melting was expedited as more CNTs were introduced. The expediting of melting was mainly attributed to the enhanced thermal conductivity and lowering of latent heat of fusion of NEPCM. The inclusion of CNTs, however, increases considerably the viscosity of melted NEPCM, which in turn leads to less significant natural convection effect during melting. As a result, increase of loading of CNTs was shown to lead to two competing effects. The feasibility of NEPCM in melting is justified when the enhanced heat conduction overweighs the suppressed natural convection.

scholarly journals Application of Phase Change Material-Based Thermal Capacitor in Double Tube Heat Exchanger—A Numerical Investigation

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4327
Author(s):  
Matthew Fong ◽  
Jundika Kurnia ◽  
Agus P. Sasmito
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Oscillation Period ◽  
Temperature Oscillation ◽  
Tube Heat Exchanger ◽  
Inlet Conditions ◽  
Change Material

In many heat transfer related applications, there is a need for a stable, constant supply temperature. As a result, the integration of intermittent renewable sources of heat into these processes can prove to be challenging, requiring special temperature smoothing devices or strategies. This study focuses on the application of phase change materials integrated into a double tube heat exchanger as a possible thermal smoothing device. The objective of this study is to evaluate the ability of the exchanger to smoothen out temperature variations within the cold stream outlet while the hot stream is subject to oscillating inlet conditions. A computational fluid dynamics approach is used where a numerical model is developed, validated and then used to model the conjugate heat transfer within the heat exchanger. Four organic phase change materials (PCM) with different phase change temperatures were selected for investigation (myristic, octadecane, eicosane, and wax) to study the relationship between melting temperature and stabilization performance. A parametric study was then conducted by varying the Reynolds number of the flow as well as temperature oscillation period and amplitude to study the sensitivity of the system. The results confirm the potential of a phase change material-based thermal capacitor at dampening oscillations across the heat exchanger.

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